Need more info? Like, did you short your 5v or 12v line on a molex connector? Did it just blow the fuse. What are you running off the power supply? ETC.....
I would check to make sure nothing is grounding out on the circuit board, then replace the fuse and try turning it on. (not connected to computer)
I have never had just a fuse blow in any of my p.s. , They usually make a bang and then start smoking.